Process for producing photographic materials

ABSTRACT

A PROCESS FOR PRODUCING PHOTOGRAPHIC MATERIALS COMPRISING CONTACTING A BI-AXIALLY STRETCHED POLYSTYRENE SUPPORT WITH A LIQUID CONTAINING AT LEAST A SOLVENT OR SWELLING AGENT FOR SAID POLYSTYRENE AND GELATIN DISPERSED THEREIN, CONTACTING THE SUPPORT WITH A NON-SOLVENT FOR SAID POLYSTYRENE TO PREPARE A WHITE OPAQUE POLYSTYRENE SUPPORT HAVING A HYDROPHILIC SURFACE, AND APPLYING AN EMULSION OR SUSPENSION CONTAINING GELATIN TO SAID SUPPORT, IS DISCLOSED.

United States Patent Oifice Patented Nov. 28, 1972 PROCESS FOR PRODUCINGPHOTOGRAPHIC MATERIALS Sumitaka Tatsuta and Wataru Ueno, Kanagawa,Japan,

assignors to Fuji Photo Film Co., Ltd., Kanagawa,

Japan No Drawing. Filed Feb. 18, 1971, Ser. No. 116,625

Claims priority, application Japan, Feb. 20, 1970, 45/ 14,938 Int. Cl.341m /14; G03c 1/76 US. Cl. 117-34 4 Claims ABSTRACT OF THE DISCLOSURE Aprocess for producing photographic materials comprising contacting abi-axially stretched polystyrene support with a liquid containing atleast a solvent or swelling agent for said polystyrene and gelatindispersed therein, contacting the support with a non-solvent for saidpolystyrene to prepare a white opaque polystyrene support having ahydrophilic surface, and applying an emulsion or suspension containinggelatin to said support, is disclosed.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates to a process for producing photographic materials having alight-sensitive layer containing gelatin or an image receiving layerwhich is used for a silver salt diffusion transfer process on a whiteopaque polystyrene support (the so-called synthetic paper).

(2) Description of the prior art Hitherto, as the support of thephotographic paper, baryta paper which is prepared by coating the paperproduced from pulp with barium sulfate has been used. However, thissupport has disadvantages, for example, expansion and contraction causedby temperature variation and especially contraction which results afterdeveloping treatment, drying after development requires a long period oftime, and the support has poor resistance in water.

Such disadvantages are resolved by using films of hydrophobic highmolecular substances, for example, a biaxially stretched polystyrenefilm as the support of the photographic printing paper.

In this case, however, the support should be whitened opaquely. Thisprocedure is carried out using a method which comprises dipping apolystyrene film in a solvent or a swelling agent for polystyrene, suchas tetrahydro furan, ethyl acetate and acetic acid, and dipping the filmthen in a non-solvent for polystyrene, such as methanol and ethanol, toform a coarse surface.

This support is markedly preferred as the support of a photographicpaper because of its excellent water resistance, drying rate,dimensional stability, rigidity, whiteness and opacity.

However, although the polystyrene has the abovedescribed excellentcharacteristics as the support of photographic printing paper, it isvery difiicult to cause a film formed from photographic emulsionscontaining hydrophilic gelatin to adhere firmly to the surface of thesup port, because it is hydrophobic and chemically inactive. As a meansof changing the hydrophobic surface into a hydrophilic one, treatmentssuch as corona discharge, electron ray application and ozone oxidation,and the like, are disclosed already in Japanese patent application No.Sho 44-98485, Sho 45-20695 and Sho 45-4163.

SUMMARY OF THE INVENTION The process by this invention, which does notcontain the above-described tWo steps, that is, comprising whiteningopaquely a transparent polystyrene support at first and then performinga hydrophilic treatment of the resulting surface, is characterized inthat photographic materials are prepared by Whitening opaquely thetransparent polystyrene support and preparing a hydrophilic surface atthe same time, and applying an emulsion or a suspension containinggelatin to the resulting surface, by which adhesion between the supportand the coating film is improved.

Namely, the present invention is a process for preparing photographicmaterials which comprises contacting a biaxially stretched polystyrenesupport with a liquid which comprises at least a solvent or swellingagent for polystyrene and gelatin dispersed therein, then contacting thesupport with a non-solvent for polystyrene to prepare a white opaquepolystyrene support having a hydrophilic surface, and applying anemulsion or a suspension containing gelatin to said polystyrene support.

DETAILED DESCRIPTION OF THE INVENTION In this invention, the emulsion orsuspension containing gelatin applied to the polystyrene means anaqueous emulsion or aqueous suspension of gelatin which can be preparedby adding or not adding a silver halide, such as silver chloride, silverbromide, silver chlorobromide and silver iodobromide, a light-sensitivediazo compound, substance of center of development of the imagereceiving material used in the silver salt diffusion transfer process,and other desired substances. After application of the aqueous gelatinsolution, the silver halide emulsion may be applied. In this case, thecoating film made from the aqueous gelatin solution is a subbing layerfor application of emulsions.

As described above, a fine porous layer is formed on the bi-axiallystretched polystyrene support by contacting said polystyrene supportwith a solvent or swelling agent thereof and then contacting the supportwith a nonsolvent for polystyrene which can be compatible with saidsolvent or swelling agent, by which said support becomes very white andopaque.

When subjected to permeation of the above-described solvent or swellingagent into the polystyrene support, if gelatin particles are dispersedin the solvent or swelling agent, the gelatin particles precipitatesimultaneously with the formation of a fine porous layer, by which thepolystyrene support becomes white and opaque and the surface thereofbecomes hydrophilic at the same time. Thus, the adhesive strengthbetween the resulting white opaque and hydrophilic polystyrene supportand a photographic emulsion layer containing gelatin or an imagereceiving coating layer in the silver salt difiusion transfer process(hereinafter, such a layer will be described as an image receivinglayer) is large both in the dry state and in the wet state ondevelopment treatment.

The solvent and the swelling agent which can be used in theabove-described treatment include, for example, methyl acetate, ethylacetate, acetone, methylethylketone, methylene chloride, ethylenechloride, tetrahydrofuran, cyclohexane, benzene, dioxane, benzylalcohol, trichlene and mixtures thereof. The non-solvent includesmethanol and ethanol and the like. In this invention, water, nonsolventsand dispersing agents may be, added suitably on dispersing the aqueousgelatin solution in said solvent or swelling agent. Further, althoughthe amount of gelatin dispersed depends upon type of solvent, from 0.1to 2.0% by weight or so is preferable.

The adhesive strength between the thus resulting support and thephotographic emulsion layer containing gelatin or the image receivinglayer does not exhibit any deterioration after the passage of longperiods of time.

Methods of testing the adhesive strength between the photographicemulsion layer or image receiving layer and the film support in examplesof this invention were as follows.

(1) Method of testing the adhesive strength in the dry state A cellulosetriacetate film of 0.14 mm. thickness is adhered to a surface of theemulsion layer or image receiving layer of the film support using anepoxy adhesive. After letting stand at 23 C., 65% RH for a day, theresulting film is cut in a strip 1 cm. in width and 15 cm. in length.The strip is then stripped off at a drawing rate of 7.38 cm./min. Thestripping strength is determined by strain gauge. In the examples ofthis invention, good adhesion means the stripping strength is largerthan 8 g./mm., which in practice is sufiicient as the adhesive strengthbetween the emulsion layer or image receiving layer and the support inphotographic materials.

(2) Method of testing the adhesive property in the wet state In steps ofdeveloping, fixing and rinsing, the same test of stripping as in theabove-described method is practiced, using a cyanoacrylate typeadhesive. Good adhesion means having a stripping strength greater than 2g./mm.

EXAMPLE 1 After dipping a bi-axially stretched polystyrene support 0.1mm. in thickness in a solution having the following composition at 20 C.for 3 seconds, the support was dipped in methanol for another 30 secondsto prepare a hydrophilic white opaque polystyrene.

Gelatin aqueous solution) cc 8 Salicylic acid (dispersing agent) g 0.3Ethylene chloride cc 50 Methanol cc 50 Formalin (20% aqueous solution)cc 0.3

To the white opaque polystyrene support having hydrophilic surfacesabove-described, a gelatin-silver halide photographic emulsion havingthe following composition per 1 111. of the film was applied:

Silver chlorobromide (chlorine:bromine=30 mols:

70 mols) g v 3.5 Gelatin 13.0 Formalin (hardening agent) 0.1 Saponin0.03

atin was not dispersed and with the above-described emulsion being thenapplied, adhesion in the dry state and the wet state was quite inferior,that is, the stripping strength was less than 2 g./ mm. in the dry stateand nearly 0 g./mm. in the wet state.

EXAMPLE 2 After dipping a bi-axially stretched polystyrene support 0.1mm. in thickness in a solution having the following composition at 20 C.for 3 seconds, the support was further dipped in methanol for 30 secondsto prepare a white opaque hydrophilic polystyrene support.

Gelatin (10% aqueous solution) cc 4 Salicylic acid (dispersing agent) g0.3 Benzene cc 50 Acetone cc 50 Formalin (20% aqueous solution) cc 0.3

To the white opaque polystyrene having hydrophilic surfacesabove-described, a coating solution of the image receiving layer used ina silver salt diffusion transfer process having the followingcomposition per 1 m. of the film was applied.

Gelatin 3 Ag S colloid 0.001 Phenylmercaptotetrazole 0.01 Saponin 0.02

EXAMPLE 3 After dipping a bi-axially stretched polystyrene support 0.2mm. in thickness in a solution having the following composition at 20 C.for 3 seconds, the support was further dipped in methanol for 30 secondsto prepare a white opaque polystyrene support having hydrophilicsurfaces.

Gelatin (10% aqueous solution) cc 8 Salicylic acid g 0.3 Methylenechloride cc 50 Methanol cc.. 50 Formalin (20% aqueous solution) cc 0.3

To the opaquely whitened polystyrene support having hydrophilicsurfaces, a gelatin-silver halide color photographic emulsion having thefollowing composition per 1 m. of the film was applied.

Silver chlorobromide (chlorine:bromine=30 mols:

70 mols) g 3.0 Gelatin g 3.5 Emulsified dispersion containingbenzoyl-aceto-Z- chloro-S-dodecyloxycarbonyl anilide (yellow coupler) g14.0 Triethylene phosphamide (3% acetone solution) ml 3.0Polyvinylpyrrolidone g 0.7

When the test of stripping the emulsion layer from the support waspracticed on the above-described color photographic emulsion coatingfilm, it exhibited satisfactory adhesive strength in both the dry stateand the wet state for the color photographic material.

On the contrary, when the transparent polystyrene was treated with theabove-described solution in which gelatin was not dispersed followed bysubsequently applying the above-described color emulsion, adhesion ofthe film was quite inferior.

What is claimed is:

1. A process for producing photographic materials which comprise aphotographic layer on a support having increased adherence between thephotographic layer and the support, said process comprising contacting abiaxially stretched polystyrene support with a liquid containing atleast a solvent or swelling agent for said polystyrene and from 0.1 to2.0% by weight of gelatin dispersed therein, contacting the support witha non-solvent for said polystyrene to simultaneously render saidpolystyrene support white opaque and having a hydrophilic surface andapplying a photographic emulsion or suspension containing gelatin to thewhite opaque hydrophilic surface of said support.

2. The process of claim 1, wherein said solvent or swelling agent isselected from the group consisting of methyl acetate, ethyl acetate,acetone, methylethylketone, methylene chloride, ethylene chloride,tetrahydrofuran, cyclohexane, benzene, dioxane, benzyl alcohol,trichlene and mixtures thereof, and wherein said non-solvent is selectedfrom the group consisting of methanol and ethanol.

3. The process of claim 1, wherein said emulsion or suspensioncontaining gelatin contains a member selected from the group consistingof a silver halide, a light-sensitive diazo compound, and a materialproviding centers of development of an image receiving material in asilver salt diffusion transfer process.

4. The process of claim 1, wherein said emulsion or suspensioncontaining gelatin forms a subbing layer.

References Cited UNITED STATES PATENTS 2,957,791 10/1960 Bechtold 96-873,515,567 6/1970 Tani et al 117--47 A 3,547,642 12/1970 Nishio et al.96-84 3,357,874 12/1967 Kennedy et al. 117-47 A 3,124,476 3/1964 Park etal. 117-47 A 3,132,983 5/ 1964 Osborne et al 117-47 A 2,790,727 4/1957I-Iilborn 117-63 2,848,752 8/ 1958 Bechtold 11736.7 3,135,622 6/19'54Ranalli 11763 3,298,895 11/ 1967 Plambecki 117-36.7 3,146,883 9/1964Harlan et al. 117--47 A WILLIAM D. MARTIN, Primary Examiner W. R.TRENOR, Assistant Examiner US. Cl. X.R.

117--l1, 47 A, 36.7, 63, 117, 138.8 UA; 96--84, 87

